An automotive fuse finding increasing use is a plug-in fuse of the type described in the U.S. Pat. No. 3,909,767. Such a fuse has a plastic body which includes an internal fusible link and a pair of parallel spaced blade contacts that extend out of the body. As befits the name, such a fuse is joined to the electrical system by plugging its blade contacts into suitable terminals that are otherwise connected to the vehicle's electrical system.
U.S. Pat. No. 4,687,270 which is assigned to the assignee of this patent application provides a convenient package for a row of such plug-in fuses, giving simplified handling and installation as well as replacement and servicing of the fuses. This package includes an insulator block with a pair of parallel rows of terminals that are adapted to receive the blade contacts of the row of fuses as they are plugged in. The terminals hold the fuse contacts with a gripping force sufficient to keep the fuses in place until they are purposely pulled out. The insulator block has two pairs of spaced ramps which are located between the rows of terminals.
The package further includes a cover adapted to be installed on and removed from the insulator block. The cover is adapted to hold a row of fuses with a holding force sufficient to maintain the fuses in the proper orientation to plug into the terminals as the cover is installed. The holding force, however, is less than the terminal gripping force so that the fuses are pulled out of the cover and remain plugged into the terminals when the cover is removed. The cover is generally in the form of an open box with a pair of spaced end walls which have shallow grooves.
The package also includes a fuse retainer which has flexible legs at its ends which resiliently snap into the shallow grooves in the spaced end walls of the cover to provide a retention force that is sufficient to prevent the fuse retainer and fuses from falling out of the cover before installation. The fuses, retainer and the cover may, therefore, be handled and installed together as a unitary assembly. This provides a very convenient means of handling and shipping the fuses. It also provides a convenient means for plugging the fuses into the insulator block terminals all at once, since the fuses are already properly oriented and held within the cover. The retainer also has a second pair of flexible legs that extend out from the retainer and that are located inboard of the flexible legs at the ends of the retainer.
As the unitary assembly of cover, retainer, and fuses is installed on the insulator block, the second pair of flexible retainer legs concurrently flex past and interengage with the two pairs of spaced ramps of the insulator block to lock the retainer to the insulator block. The locking force provided by the engagement of the second pair of flexible legs with the spaced ramps is greater than the retention force provided by the engagement of the flexible legs at the ends of the retainer in the shallow grooves of the cover. Therefore, the retainer stays with the insulator block when the cover is removed, and the fuses conveniently remain with the insulator block for easy individual access and removal. The cover may then be reinstalled, and will be retained to the block as before.